Merge branch '2018.1' of https://github.com/Unity-Technologies/ScriptableRenderPipeline into 2018.1

ScriptableRenderPipeline/Core/CoreRP/Debugging/Prefabs/Scripts/UIFoldout.cs

         public GameObject arrowOpened;
         public GameObject arrowClosed;
 
-        protected override void Awake()
+        protected override void Start()
-            base.Awake();
+            base.Start();
             onValueChanged.AddListener(SetState);
             SetState(isOn);
         }
             if (arrowOpened == null || arrowClosed == null || content == null)
                 return;
 
-            arrowOpened.SetActive(state);
-            arrowClosed.SetActive(!state);
-            content.SetActive(state);
+            if (arrowOpened.activeSelf != state)
+                arrowOpened.SetActive(state);
+
+            if (arrowClosed.activeSelf == state)
+                arrowClosed.SetActive(!state);
+
+            if (content.activeSelf != state)
+                content.SetActive(state);
 
             if (rebuildLayout)
                 LayoutRebuilder.ForceRebuildLayoutImmediate(transform.parent as RectTransform);